 Long known for its anesthetic properties, ketamine is increasingly being used as a treatment for depression. A new study investigating the effects of this drug on the brain sheds light on the dose-dependent properties of ketamine, and provides future researchers with a strategy to monitor its neurological effects. Distinct molecular, neural, and behavioral features of ketamine set it apart from other general anesthesia medications. In addition to its use as an analgesic, ketamine can be used in low doses to treat mood disorders. But the precise neurophysiological effects of this drug at different doses remain unclear. As this medication becomes more frequently used in various therapeutic settings, a detailed understanding of these effects is important. Using dosing strategies relevant to clinical care for depression and anesthetic induction, a research team at the University of Michigan administered anesthetic and sub-anesthetic doses of ketamine to 10 healthy volunteers. In the experiment, EEG electrodes were used to monitor electrical brain activity. This allowed the researchers to create high-resolution maps visualizing the effects of different drug concentrations on the brain. They found the effects of ketamine to be highly dose-dependent. Clear differences in spectral power and functional connections across the brain were observed between the two dosing schemes. Certain processes thought to be important for normal neurological function, such as coordinated activity, only became disrupted when anesthetic levels of ketamine were administered. These anesthetic doses resulted in distinct increases in theta power and functional connectivity. By contrast, anterior-posterior connectivity in the alpha bandwidth was maximally reduced in the anesthetized state. This study provides researchers and physicians with important insights into the effects of ketamine dosing on brain activity and its anesthetic properties. Furthermore, as ketamine becomes used more frequently for various medical applications, it will be important to have strategies to closely monitor the brain and distinguish between the drug's sub-anesthetic and anesthetic effects. The approach taken in this study provides a practical way to do just that.